1. Field of the invention
The present invention relates to a room lamp.
2. Related art
A vehicle is usually furnished with a sun-visor for shading backlight. Some of the sun-visors are often provided with miniature mirrors aside from rearview mirrors.
In case of providing the mirror to the sun-visor, for using the mirror even at night, the room lamp is sometimes furnished near a windshield glass in a ceiling. The room lamp is apart from a doom lamp furnished near the center of the ceiling.
Further, the room lamp is disposed at a position to be hidden by the sun-visor when the sun-visor is folded toward the ceiling. The room lamp is very small sized comparing with a doom mirror, since it is used only when using the mirror.
Besides, the mirror of the sun-visor is often furnished with a cover opening and closing by sliding. The sun-visor is sometimes so constructed as to light the room lamp when opening the cover.
FIG. 15 is a disassembled view of a prior art room lamp 1. The room lamp 1 comprises a design part 11 and a function part 12 detachably attached to the design part 11. The design part 11 comprises a frame shaped bezel 13, a lens 15 provided over an opening 14 of the bezel 13, and clips 16 provided at both sides of the bezel 13. In addition, the function part 12 has a bulb (an electric lamp) 17 and a function main body 18.
The room lamp 1 is, as shown in FIG. 16, mounted in an opening 20 formed in a trim (an interior finish material) in the ceiling of a vehicle. In this case, the room lamp 1 is supported by catching the clips 16 thereof at the edge of the opening 20. By the way, numeral 22 in FIG. 16 is an electric cable connected to the function main body 18, and numeral 23 is a car body (a metal).
In regard to the function part 12 of the room lamp 1, as shown in FIG. 17, a concave part 24 is defined in the function main body 18, and the concave part 24 is furnished therein with pressure cutting-edges 25. The pressure cutting-edges 25 are formed at distal portions with V-shaped grooves 25a, and are connected to the bulb 17. The concave part 24 is provided with an opening-closing cover 26.
The flat cables 22 are connected to the function part 12, as shown in FIG. 18, by inserting the flat cables 22 in the concave part 24 and putting them in the V-shaped grooves 25a formed at the distal portions of the pressure cutting-edges 25, and as shown in FIG. 19, when the cover 26 is closed, the flat cables 22 are pushed toward the pressure cutting-edges 25, and insulating films of the flat cables 22 are broken by the pressure cutting-edges 25, so that cores thereof are electrically connected to the pressure cutting-edges 25. The flat cables 22 are thereby connected to the bulb 17 via the pressure cutting-edges 25.
Herein, the cover 26 is formed, on a face at the side of the pressure cutting-edges 25, with projections 26a for pressing the flat cables 22. A space between the projections 26a and 26a is substantially flat. The flat cables 22 are securely urged into the grooves 25a by the projections 26a. 
Next, explanation will be made to a method of attaching the above mentioned room lamp 1 to the ceiling trim 19 of the vehicle. On the ceiling trim 19 to be attached with the room lamp 1, as shown in FIG. 20, there are formed a hole 30 for attaching the doom lamp and holes 31 for attaching the room lamps (called as “room lamp attaching hole(s)” hereafter).
At first, as shown in FIG. 21, in the room lamps attaching holes 31 in the ceiling trim 19, an only design part 11 of the room lamp 1 is attached. Next, as shown in FIG. 22, the function part 12 is in the design part 11. The flat cable 22 has been in advance connected to the function part 12. Subsequently, as shown in FIG. 23, the ceiling trim 19 is attached to the ceiling 32a of the vehicle main body 32.
For exchanging the bulb 17 of the room lamp 1, as shown in FIG. 24, the whole of the room lamp 1 is removed from the ceiling trim 19. At this time, for avoiding action of tension on the flat cable 22, the flat cable 22 has an extra part 22a. 
The extra parts 22a of the flat cables 22 are, as shown in FIG. 25, held by clips 33 provided to the function part 12. As shown in FIG. 26, the clips 33 are formed to be almost L-shape. In the space between the clip 33 and the function main body 18, the flat cables are inserted and held.
A space b1 between both insides of the clip 33 is formed to be almost the same as an inserting width b2 of the flat cables 22. Further, on the insides of the clip 33, catching pawls 34 are formed to be mutually opposite, and between the catching pawls 34, 34, an insertion passage 35 is defined for inserting the flat cables 22 inside of the clips 33.
These structure are shown in Unexamined Japanese Patent Publication 2002-67789, 2002-218635 and 2002-345143.
However, the prior art room lamp 1 has been involved with a problem that since the design part 11 has two pieces of clips 16 at both sides thereof for attaching the room lamp 1 to the ceiling trim 19, the room lamp 1 and the room lamp attaching holes 31 in the ceiling trim 19 are large sized. This case has another problem that the room lamp 1 is expensive.
FIG. 27 disassembled views of a prior art room lamp 120 to be attached to a substantial center part of a ceiling face of a vehicle as shown in Unexamined Japanese Patent Publication 2003-40032.
The room lamp 120 has a design part B and a function part A detachably attached to the design part B. The design part B has a frame shaped housing 141, a lens 181 furnished in the housing 141, and catching pawls 142 provided at both sides of the housing 141. The function part A has a bulb (an electric lamp) 124 and a function main body 121, and is attached to an opening 146 of the housing 141.
Further, the room lamp 120 has fixtures 143, flexible arms 147, and flexible arm controllers 147a, said fixtures 143 being provided vertically toward a side of a reinforce 160 of the housing 141 for mutually fixing the room lamp 120 and the reinforce 160 of the vehicle, said flexible arms 147 being bend in a reverse U-shape and engaged at its front end with an attaching part 183 of the reinforce 160, and said flexible arm controller 147a being disposed at the side of the flexible arms 147 and engaged with supporting pieces 145 of the flexible arms 147 in order to control front ends being displacing along an attaching-detaching direction of the room lamp 101.
FIG. 28 shows another room lamp 101 of the prior art to be attached to the substantial center part of the ceiling face of the vehicle as shown in Unexamined Japanese Patent Publication 2002-127819.
The room lamp 101 is formed with an opening 185 in a skeletal member to be fixed to the side of an interior of a roof panel, and has a first engaging instrument 106 formed along the opening 185, second engaging instruments 107 projecting from end parts 185b of the opening 185, and third engaging instruments 108 arranged in positions along the end part 185b of the opening 185.
The room lamp 101 is provided with first and second pawls 111, 112 engaging with the first and second engaging instruments 106, 107, and mounting instruments 113 enabling to mount on the third engaging instruments. The room lamp 101 interposes a previously set up roof trim 104 and is engaged with and supported by the skeletal member 102.
However, the room lamp 120 shown in FIG. 27 has had a problem that a fixture 143 is necessary for fixing the room lamp 120 to the reinforce 160, so that a structure is made complicated and invites cost-up.
Another problem is that the side of the vehicle needs the reinforce 160, and increases the number of parts to invite cost-up.
A further problem is that since the room lamp 101 shown in FIG. 28 necessitates a skeletal member 102 for securing the room lamp 101 to the side of the vehicle, the number of parts increase to invite cost-up. A still further problem is that since engaging measures 106, 107 are also necessary to fix the skeletal member to the side of the room lamp 101, a structure is made complicated and cost goes up.